What is CNC Drilling? Working, Advantages, and Applications

CNC drilling machines offer a wide range of options for designing precise, quality-controlled, and highly tolerant stationary workpieces. Since it is an automated process, every manufacturing industry working with materials from metal to wood employs CNC drilling.

In this article, we’ll begin by understanding the fundamentals with a focus on ‘What is CNC Drilling’. Then, its operations inch by inch, the benefits, the vital tips, and considerations provided will assist in advancing the efficiency and accuracy level of CNC drilling. Moreover, we’ll walk through the materials that need CNC drilling and workable tips with a lot more.

CNC Drilling Defined

It is a computer-automated machining process that creates holes in stationary work pieces with the medium of a rotating drill. The generated holes serve the purpose of housing screws or bolts for assembly purposes and sometimes for aesthetic purposes conditioned by workpiece design.

CNC Drilling

CNC drilling is mostly employed for the mass production of components in manufacturing industries. Unlike manual drilling, it performs drilling operations by automatically dictating the program code for making accurate and sophisticated designs.  

Working Mechanism of CNC Drilling

Comparable to other CNC machining processes, CNC drilling also has multiple steps by which it completes the whole drilling process. Here is a beginner’s guide to the CNC drilling mechanism

Step 01: CAD file formation

This stage starts with the creation of the component’s digital design through CAD software, such as (Fusion 360, Autodesk Inventor, and Solidworks). This design contains the technical figures for instance dimensions, tolerance and diameter etc.

Step 02: Exporting and converting the design into machine codes

After finalizing the component design, now is the time to convert it into language digestible by the CNC machine unit. The machine codes were generated after putting the CNC design through CAM software. For a detailed understanding of handling CNC files and CAD formats, consult the ‘Guide to CNC Files and CAD formats’. This resource will provide comprehensive information to facilitate smooth information in CNC machining.

Step 03: Selecting the suitable drilling cycle

Depending upon the specific requirement of component design, there are three drilling cycles. G73: Within the operative blade length, it can produce a hole depth of more than three times the drill diameter: G81; is ideal for chamfering and center holes not crossing three times the drill diameter. G83; only applicable for deep hole processing.

Step 04: Selecting the appropriate tools and tool holders

Every drill bit has its specifications in hole creation. In particular, twist drills for versatility and deep or center drills for specific purposes. The hydraulic chuck, collet chuck, and end mill holder are some tool holder preferences. The selection of the tool holder depends on tool overhanging, tapper type, and shank compatibility.  

Step 05: Executing the drilling operation

Before the drilling operation, the drill bits are carefully placed and the workpiece is secured. Next, the machine codes are fed to the drilling machine to streamline the setup process. Now execute the operation. The automated machine system specifies drilling depths, and diameter and adjusts the feed rate, and speed, guaranteeing the proper and efficient outcomes.  

Bore vs Drill: A Key Difference

The Bore vs. Drill is somewhat interrelated and sometimes creates confusion for new operators in the CNC machining industry.  

Both operations are done with the help of drilling machines, but there is a big difference between them. Drilling creates a hole in the workpiece, on the other hand, enlarging or expanding the pre-existed hole is known as drilling. In drilling, we use drill bits. On the contrary, a boring bar is employed for boring operations. 

Afterward, the technician inspects the final workpiece for any imperfections and forwards it for some post-processing finishing. 

Types of CNC Drilling Machines

There are multiple types of CNC drilling machines available in the market with different configurations, capacities, and features. Let’s go through each type and understand their specifications.

• Upright CNC Drill Press: It is available in both manual and CNC types. Majorly it is employed for oversized and heavy component drilling. The machine contains a gear drive spindle head which enables swift drilling through the heftiest material.
• Radial arm drill press: The radial arm drill press is renowned for its flexibility and versatility.  A movable spindle is positioned over the workpiece which enables it to execute multiple drilling operations.
• Gang drilling machine: The machine embodies various drilling heads placed over the stationary workpiece. It can simultaneously perform successive drilling operations on a single workpiece without any type of hindrance.
• Multiple spindle drilling machine: As the machine’s name implies it contains several spindles. It can accommodate several drilling heads and, therefore, allows the production of several holes in the component.
• Micro drill press: Micro drill press is used for products requiring high accuracy and tolerance. It has small chunks designed for achieving appropriate drilling even for medical part manufacturing. 
• Turret-Type Drilling Machine: The machine has numerous work heads housed by the turret (rotary tool holder). It is suitable for work requiring consistent tool changes to perform diverse operations on a single workpiece.

Advantages of CNC Drilling

The automation process of CNC Drilling Machines shows superiority over manual drilling due to precision, flexibility, and efficacy. Below mentioned are the benefits, CNC drilling machines offer;

1. Safe handling of sophisticated drilling tasks 

The manual handling of complex drilling processes was challenging in the past. Thanks to CNC drilling machines striking complex tasks down much more easily with premium outcomes. Consistent drilling of multiple holes with different sizes and diameters can be accomplished by CNC machining.

2. Greater reproducibility

The computer-controlled process ensures accuracy and there is almost no space for errors. The manufacturer can finish large-scale projects in a shorter time and can attain consistency between multiple workpieces.

3. Precision, validity, and versatility

These three words can be considered synonyms of CNC drilling. Due to automation, the drilled holes are exactly like the original design. A wide array of materials e.g. wood, metal, and plastic can be used for CNC drilling.  

Vital Considerations for Sound CNC Drilling

Although CNC drilling seems like a simple process, certain processes need technical assistance. There are a few practical tips you can follow to achieve the desired drilling results.

1- Prefer the relevant drilling head: 

The selection of the drilling bit depends on the function, material, and structure. Many of the drilling defects can be eliminated by choosing the right drilling bit. Commonly used drill bits and their applications are enlisted below:

• Step drill: Fit for drilling holes of various diameters in aluminum.
• Twist drill: Suitable for drilling in walls, wood, etc.
• Indexable drill:  Capable of making holes about 5 times the diameter.   
• Center drill: Employed for generating starting points for drilling.
• Ejector drill: Generate deep holes ranging between 19 and 102 mm.

Drill bits types

Below are some other drill types, their sizes, and applications, being used in machining industries respective to the material they are used against. 

Table: Drill types used for metal drilling and their applications in the manufacturing industry.

2. Optimizing speed and feed rate: 

Correct balance amid feed rate and cutting pace is the key component in CNC drilling for obtaining productiveness. The cutting speed depends upon the material type, material diameter, and hole depth. There are certain tools available online to compute feed rates.

3. Chip removal and breaking: 

Improper chip removal can cause several complications. So, To avoid this problem, you should;

• Use specially designed chip-breaking drill bits to tear chips into manageable pieces, which in turn eases the chip removal process.
• Adjust the feed rate to a limit so that it can expedite the chip removal process, normally, it is recommended that the feed rate should be increased.
• Install chip braking device enables chip control by sizing the pieces during drilling.
• The use of intermittent feed has presumably resulted in chip evacuations.  

Applications of CNC Drilling

CNC drilling technology has been used by numerous modern manufacturing industries. Here are the detailed applications of CNC drilling industry-wise.

Metal Fabrication

CNC drilling creates structurally accurate and fitting holes in solid metal, thereby becoming a sound choice for industries working with sheet metal such as aerospace and automotive. Basic components like engines, turning wheel hubs, gear banks, dashboards, and custom shafts need drilling.

Wood Manufacturing

CNC drilling is the central element of wood-crafting industries. From shaping wooden workpieces to structuring sophisticated furniture design, CNC drilling machines help along the way, crafting the aesthetic product.    

Electrical Industry

In creating microscopic components of computer and electrical appliances, CNC drilling plays a vital role. The rapid production rate of miniature components for instance microchips, motherboards, and cover cases needs highly efficient CNC drilling. 

Why Embrace Prolean for your CNC Drilling Needs?

Our customized drilling cost estimation will provide coherent, accurate, and finally tuned holes that will amaze you. We manufacture high tolerance, simple to complex holes across a broad spectrum of materials from plastic to metal. We are more than determined to meet the highest standard of drilling quality.   

Alongside this, we also cover the component assembly here at Prolean with perfect final finishing. So, send us your project and get a quote from our experts today!

Summing Up

CNC drilling is accelerating the manufacturing industries by bringing into being sophisticated intricate workpiece designs for assembly purposes. The one unique quality of CNC drilling is that it needs pre-programming which eliminates any type of error in the final product. There are several types of CNC drilling machines with different specifications and framing allowing the technician to forge multiple holes at the same time in a single stationary workpiece.  

FAQs

What is the difference between CNC milling and drilling?

A CNC machine drills through the workpiece vertically but on the other hand if we discuss CNC milling, it works vertically, horizontally, and diagonally.

What is threading in drilling?

The term threading refers to the creating hole for a bolt to pass through which is accomplished by combining various processes for instance CNC drilling, milling, and thread tapping.

What is the maximum hole depth achievable with CNC drilling?

Depending upon the machine specification and drill bit, a CNC drill can easily handle a depth 5 times the diameter.  

Is CNC drilling a cost-effective process?

Remember that the CNC Drilling Cost is determined by the drilling requirement and project specificity. It depends upon various factors, including, initial purchase cost, operational cost, tooling cost, material cost, labor cost, and overhead cost. 

What CNC drilling head is used for wood?

Well, the most appropriate drilling head used for wood is a twist drill. It can swiftly pass through the wooden workpiece up to the required depth.